This invention relates to an improved yarn package carrier of the type used to support numerous packages of yarn in vertically-spaced relation on a plurality of upright spindles within a pressure kier. Pressure kiers typically have cylindrical side walls and a dome-shaped cover to seal closed the top opening. The kier must be able to withstand high internal pressures. As a result, the kier cover is dome-shaped to disperse the pressure within the kier more evenly and to more easily withstand the stress on its structural parts.
Pressure kiers are very commonly used to package dye yarns manufactured of various synthetic as well as natural fibers, and are almost indispensible in the dyeing of large, tightly wound packages of nylon and orlon, among others.
While dyeing with a combination of high pressure and heat is still the best means of applying a high quality dye to these types of yarns and fibers, the greatly increasing cost of energy and hydrocarbon-derived dyestuffs necessitates a more effective and efficient means of carrying out these processes. Even though the various dyeing equipment manufacturers can be expected eventually to develop new and much more efficient dyeing machinery, there exists a vast quantity and variety of older and relatively inefficient equipment in place which still has many years of useful life left but is becoming increasingly expensive to operate because of the greatly increasing cost of energy and dyestuffs.
It has been observed that all dome-covered pressure kiers, even those with very high pitched domes, are provided with yarn carriers, the spindles of which are all the same length and carry the same number of yarn packages. Invariably, these spindles extend to below or just even with the top opening of the kier. As a result, the area enclosed within the dome-shaped cover constitutes a large amount of essentially wasted space, since, while it must be filled with extremely hot water or air, it is not contributing to the productivity and efficiency of the kier. Furthermore, while it has not been heretofore recognized, it appears that the unoccupied space enclosed within the dome-shaped cover of a pressure kier contributes to poor quality dyeing by permitting foam to accumulate in the top of the kier, resulting in light or faded spots in the yarn packages carried near the top of the yarn carrier spindles.